A cortical area is a spatially confined unit of the cerebral cortex. Often, such a unit is functionally defined, i.e. its neurons share certain distinguishing properties. For instance, they get activated by the same category of stimuli or seem to be involved into similar cognitive tasks, that are different from the stimuli or tasks that activate neurons in the neighboring areas. Alternatively, cortical areas can be defined histo-anatomically, like the Brodmann areas. In some cases, both types of definition yield identical areas. An example is the primary visual cortex, known as V1, which is identical to Brodmann area 17.